The
thickness and profile (width) of the blade are connected to their designed usage.
Broad and thin blades were forged for cutting swords, while narrow and thick
blades were forged for thrusting swords. Unlike public believe, thrusting
swords are thicker than cutting swords. It makes sense when one considers the
physics of the actions. In cutting, one would like to reduce the friction generated
during penetration and the thinner the blade, the easier to get through. In
thrusting, one would like the force to focus on the tip and the stouter the
blade, the less force is lost to the lateral vibrations. So it is no
surprising anymore that some Chinese Dao are thinner than Chinese Jian
for the former were cutting swords. By the same logic, one can understand why
would an Italian rapier, a single handed civilian dueling thrusting sword
could match a Scottish claymore, a two handed big cutting sword in terms of
thickness.

A Chinese Jian is thicker than a Chinese Dao due to the usage
difference.

A broad blade European cutting sword is
actually very thin.

When
compare to the European single-handed civilian cut and thrust sword, Chinese Jianwere often thicker but narrower. Also, they
were often lighter in total weight but with a balance more forward. It was
because the hilt portion of
Chinese Jian
was lighter than the one of cut and thrust sword. Thus by looking at the
usage of cut and thrust sword, one can tell that the Chinese Jian
were also used in cut and thrust fashion, while emphasizing more on thrusts due to the stout blade and Dian technique due
to the more forward balance.

Slice
and cut are two different things. Slice is done by serration action like a
saw removing materials from a piece of wood. Cut is done by penetrating
material by splitting them open. The more curve a sword is, the more slicing
element it has in action.

Among
cut, slice and thrust, cut has the most powerful stopping ability because it
severs muscle tissues instantly. Thrust comes in second because of the depth of the
wound and the amount of pain inflicted. Slice comes in third. However, when
dealing with armor, thrust is the best way to penetrate it because of the
concentrated pressure at a tiny point. Cut's penetrating power is vastly
diminished and only the impact power stays. Hence, armored fighting techniques differ
from unarmored fighting techniques with heavier emphasizes on thrusting and
grappling.